332 HEART DISEASES [VOL. vi
fhe times as great in men as in women for the aortic valves (676 to 129).
As regards age. 60 per cent of the aortic cases, but less than 40 per cent
of the mitral cases, occurred after forty years of age.
Two recent series have been selected for discussion because they were
collected from \ery different sources and yet show a reasonable measure
of agreement in the type of valvular disease likely to be found. In
Cabo:'s series, based on 4,000 consecutive necropsies at the Massa-
chusetts General Hospital, about 1,500 showed some cardiovascular
lesion, but of these less than 300 (18 per cent) showed any valvular
disease: in Grant's series, based on 1,000 army pensioners with heart
disease, 857 had valvular disease of the heart, this much higher incidence
depending on the high proportion of young adults in whom valvular
disease is more and pure myocardial disease is less common. In so far
as these series agree they are of great value owing to the large numbers,
the care with which they were studied, and the different sources
from which they were collected. In Cabot's series 42 per cent of
those with valvular disease had mitral disease alone, 24 per cent
combined lesions, and 34 per cent aortic disease alone; the corresponding
figures in Grant's series were 28, 22, and 50 per cent, the number with
aortic disease being higher than in Cabot's series, and indeed higher
than usual, because so many young patients with obvious mitral
stenosis would have been excluded from the army. The relative incidence
of the rheumatic and syphilitic cases agrees very closely, the latter
forming 18 and 22 per cent of the total, which is rather surprising
considering the diiferent methods of selection.
The cases with mitral stenosis alone need not be considered further,
and they have been omitted from Table I. It is agreed that disease of the
aortic vaKes is generally due to rheumatism or syphilis, but the relative
importance of these two conditions is very differently estimated. In
some series (Allan; Hubert) most of the cases have been considered
syphilitic, whereas in others (Russell Wells) nearly all under forty have
been said to be rheumatic. In a series I collected, consisting of 296 cases
with disease of the aortic valves, acute rheumatism accounted for four
out of each six (two-thirds), syphilis for rather more than one in six,
and atheroma and all other causes for less than one in each six. A less
personal view may be obtained by comparing these series of Cabot,
Grant, and Campbell, and the result is shown in Table I.
In the largest group (more than a third of all the cases) both the mitral
and aortic valves were affected. The second largest group (almost exactly
one-third) contained those with pure aortic disease of rheumatic origin,
the proportion with stenosis being differently estimated, because
Grant's series automatically excluded the most severe cases of rheum-
atism in the young, in whom stenosis is most likely to follow, and
Cabot's post-mortem series revealed stenosis ia several cases in which
it was not diagnosed clinically. The third largest group (less than a
third) was of syphilitic aortic regurgitation. The general conclusion
from these three series is that aortic disease may reasonably be classified